If you have any video of the tricks, go back, look at it, watch yourself doing the tricks, and ask yourself if you're happy with how it looks. Is it consistent, can you do it really well every time? Those should be some determining factors on how much you have progressed, not your friends.

There is more to freestyle skiing than just spinning as fast as you can and hoping you land it. A lot of times the skiers I look up to in the park aren't even doing that impressive of tricks, but the tricks they are doing they're doing with a ton of style! Stop focusing so much on what tricks you're doing, and start focusing a little more on how you are doing them and how they look!

Depends on what you want to achieve, whether its to be able to compete in comps, to go pro, to be good at claiming, to have everyone on newschoolers hate you, etc. It really all depends on you, and where you want to go.